Daylighting is the opening up and restoration of a previously buried watercourse, one which had at some point been diverted below ground. Typically, the rationale behind returning the riparian environment of a stream, wash, or river to a more natural above-ground state is to reduce runoff, create habitat for species in need of it, or improve an area's aesthetics. In the United Kingdom, the practice is also known as deculverting.

In addition to its use in urban design and planning the term also refers to the public process of advancing such projects. According to the Planning and Development Department of the City of Berkeley, "A general consensus has developed that protecting and restoring natural creeks' functions is achievable over time in an urban environment while recognizing the importance of property rights."

Natural drainage systems help manage stormwater by infiltrating and slowing the flow of stormwater, filtering and bioremediating pollutants by soils and plants, reducing impervious surfaces, using porous paving, increasing vegetation, and improving related pedestrian amenities. Natural features—open, vegetated swales, stormwater cascades, and small wetland ponds—mimic the functions of nature lost to urbanization. At the heart are plants, trees, and the deep, healthy soils that support them. All three combine to form a "living infrastructure" that, unlike pipes and vaults, increase in functional value over time.

Some efforts to blend urban development with natural systems use innovative drainage design and landscaping instead of traditional curbs and gutters, pipes and vaults. One such demonstration project in the Pipers Creek watershed reduced imperviousness by more than 18 percent. The project built bioswales, landscape elements intended to remove silt and pollution from surface runoff water and planted 100 evergreen trees and 1,100 shrubs. From 2001 to 2003, the project reduced the volume of stormwater leaving the street in a two-year storm event by 98%. Such a reduction can reduce storm damage to water quality and habitats for species such as the iconic salmon. Unfortunately, the engineering alternatives have a relatively expensive initial price, since they are usually replacing existing structures, albeit life-limited ones. Further, conventional systems generally do not consider full cost accounting. The natural drainage system alternatives can also provide returns on investment by improving urban environments.

The street edge alternatives street breaks most of the conventions of 150 years of standard American street design. Narrow, curved streets, open drainage swales, and an abundance of diverse plants and trees welcome pedestrians as well as diverse species. Adjacent residents maintain city infrastructure in the form of street "gardens" in front of their homes, visually integrating the neighborhood along the street. The natural drainage system united the community visually, environmentally, and socially. The 110th Cascades SEA (2002–2003) are a creek-like cascade of stair-stepped natural, seasonal pools that intercept, infiltrate, slow and filter over 21 acres (85,000 m²) of stormwater draining through the project.

Viable, daylighted streams exist only where neighbourhoods are intimately connected to restoration and stewardship values in their watersheds, since the health of an urban stream can not long survive carelessness or neglect. With impervious surfaces having replaced most of the natural ground cover in urban environments, habitat for wildlife is dramatically reduced compared to historic baselines. Hydrologic changes have resulted, and impervious waterways directly carry non-point pollution through urban creeks. One effective solution is to restore streams and riparian habitat. This improves the entire urban watershed, far beyond the riparian channel itself. Wild et al 2011 described the first known online map and database of urban river daylighting projects. Wild et al 2019 published geo-spatial database about all schemes. University of Waterloo documented a very similar list featuring many of the same stream daylighting projects around the globe.

In the 1880s there were over 50 wild salmon streams in Vancouver alone. However, as Vancouver grew, these streams were lost to urbanization. They were covered by roads, homes, and businesses. They were also lost when they were buried beneath sewers or culverts.

The City of Vancouver and its residents are now making an effort to uncover these lost streams and restore them back to their natural state.